diff --git a/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/GProcessor.java b/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/GProcessor.java
index 2ea88f9..78f2cda 100644
--- a/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/GProcessor.java
+++ b/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/GProcessor.java
@@ -11,6 +11,8 @@ import io.gitlab.jfronny.commons.serialize.generator.core.value.ValueCreator;
 
 import javax.annotation.processing.Messager;
 import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.AnnotationValue;
+import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.type.TypeMirror;
 import java.io.*;
@@ -19,8 +21,10 @@ import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.function.UnaryOperator;
+import java.util.stream.Stream;
 
 public abstract class GProcessor {
     protected final ValueCreator valueCreator;
@@ -69,13 +73,26 @@ public abstract class GProcessor {
         return null;
     }
 
-    protected String getSerializedName(Property<?> property) {
+    protected List<String> getSerializedNames(Property<?> property) {
         for (AnnotationMirror annotationMirror : property.getAnnotations()) {
             if (annotationMirror.getAnnotationType().asElement().toString().equals(Cl.SERIALIZED_NAME.toString())) {
-                return (String) annotationMirror.getElementValues().values().iterator().next().getValue();
+                String value = null;
+                List<String> alternate = null;
+                for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : annotationMirror.getElementValues().entrySet()) {
+                    switch (entry.getKey().getSimpleName().toString()) {
+                        case "value" -> value = (String) entry.getValue().getValue();
+                        case "alternate" -> alternate = ((List<?>) entry.getValue().getValue()).stream()
+                                .map(s -> (AnnotationValue) s)
+                                .map(s -> (String) s.getValue())
+                                .toList();
+                    }
+                }
+                if (value == null) value = property.getName();
+                if (alternate == null) return List.of(value);
+                return Stream.concat(Stream.of(value), alternate.stream()).toList();
             }
         }
-        return property.getName();
+        return List.of(property.getName());
     }
 
     protected MethodSpec.Builder extension(MethodSpec.Builder method) {
diff --git a/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/InstanceProcessor.java b/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/InstanceProcessor.java
index 1d65ff0..6fee779 100644
--- a/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/InstanceProcessor.java
+++ b/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/InstanceProcessor.java
@@ -81,12 +81,12 @@ public class InstanceProcessor extends GProcessor {
                 Runnable writeGet = () -> code.add("value.$N", param.getCallableName());
                 if (param.getType().getKind().isPrimitive()) {
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, writeGet);
                 } else {
                     code.beginControlFlow("if (value.$N != null || writer.isSerializeNulls())", param.getCallableName());
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     code.addStatement("if (value.$N == null) writer.nullValue()", param.getCallableName());
                     code.beginControlFlow("else");
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, writeGet);
@@ -98,13 +98,13 @@ public class InstanceProcessor extends GProcessor {
                 if (isIgnored(param)) continue;
                 if (param.getType().getKind().isPrimitive()) {
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, () -> code.add("value.$N()", param.getCallableName()));
                 } else {
                     code.addStatement("$T $L$N = value.$N()", param.getType(), "$", param.getCallableName(), param.getCallableName());
                     code.beginControlFlow("if ($L$N != null || writer.isSerializeNulls())", "$", param.getCallableName());
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     code.addStatement("if ($L$N == null) writer.nullValue()", "$", param.getCallableName());
                     code.beginControlFlow("else");
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, () -> code.add("$L$N", "$", param.getCallableName()));
@@ -148,24 +148,30 @@ public class InstanceProcessor extends GProcessor {
                         .beginControlFlow("switch (reader.nextName())");
                 for (Property<?> param : properties.names) {
                     if (isIgnored(param) && getAlternative(properties, param) == null) continue;
-                    code.beginControlFlow("case $S ->", getSerializedName(param));
-                    if (param.getType().getKind().isPrimitive()) {
-                        code.add("_$N = ", param.getName());
-                        Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
-                        code.add(";\n");
-                    } else {
-                        code.beginControlFlow("if (reader.peek() == $T.NULL)", Cl.GSON_TOKEN)
-                                .addStatement("reader.nextNull()")
-                                .addStatement("_$N = null", param.getName());
-                        code.unindent().add("} else _$N = ", param.getName());
-                        Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
-                        code.add(";\n");
+                    List<String> names = getSerializedNames(param);
+                    for (String serializedName : names) {
+                        code.beginControlFlow("case $S ->", serializedName);
+                        code.addStatement("if (has_$N && !reader.isLenient()) throw new $T($S)", param.getName(), Cl.MALFORMED_DATA_EXCEPTION, "Duplicate entry for: " + names.getFirst());
+                        if (param.getType().getKind().isPrimitive()) {
+                            code.add("_$N = ", param.getName());
+                            Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
+                            code.add(";\n");
+                        } else {
+                            code.beginControlFlow("if (reader.peek() == $T.NULL)", Cl.GSON_TOKEN)
+                                    .addStatement("reader.nextNull()")
+                                    .addStatement("_$N = null", param.getName());
+                            code.unindent().add("} else _$N = ", param.getName());
+                            Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
+                            code.add(";\n");
+                        }
+                        code.addStatement("has_$N = true", param.getName());
+                        code.endControlFlow();
                     }
-                    code.addStatement("has_$N = true", param.getName());
-                    code.endControlFlow();
                 }
-                code.add("default -> ")
-                        .addStatement("reader.skipValue()");
+                code.beginControlFlow("case String s -> ")
+                        .addStatement("if (reader.isLenient()) reader.skipValue()")
+                        .addStatement("else throw new $T($S + s)", Cl.MALFORMED_DATA_EXCEPTION, "Unexpected name: ")
+                        .endControlFlow();
 
                 code.endControlFlow()
                         .endControlFlow()
diff --git a/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/StaticProcessor.java b/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/StaticProcessor.java
index 3bdaa4e..5f2b53f 100644
--- a/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/StaticProcessor.java
+++ b/commons-serialize-generator/src/main/java/io/gitlab/jfronny/commons/serialize/generator/gprocessor/StaticProcessor.java
@@ -46,12 +46,12 @@ public class StaticProcessor extends GProcessor {
                 Runnable writeGet = () -> code.add("$T.$N", self.getTypeName(), param.getCallableName());
                 if (param.getType().getKind().isPrimitive()) {
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, writeGet);
                 } else {
                     code.beginControlFlow("if ($T.$N != null || writer.isSerializeNulls())", self.getTypeName(), param.getCallableName());
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     code.addStatement("if ($T.$N == null) writer.nullValue()", self.getTypeName(), param.getCallableName());
                     code.beginControlFlow("else");
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, writeGet);
@@ -63,13 +63,13 @@ public class StaticProcessor extends GProcessor {
                 if (isIgnored(param)) continue;
                 if (param.getType().getKind().isPrimitive()) {
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, () -> code.add("$T.$N()", self.getTypeName(), param.getCallableName()));
                 } else {
                     code.addStatement("$T $L$N = $T.$N()", param.getType(), "$", param.getCallableName(), self.getTypeName(), param.getCallableName());
                     code.beginControlFlow("if ($L$N != null || writer.isSerializeNulls())", "$", param.getCallableName());
                     generateComments(param, code);
-                    code.addStatement("writer.name($S)", getSerializedName(param));
+                    code.addStatement("writer.name($S)", getSerializedNames(param).getFirst());
                     code.addStatement("if ($L$N == null) writer.nullValue()", "$", param.getCallableName());
                     code.beginControlFlow("else");
                     Adapters.generateWrite(param, spec, code, typeVariables, otherAdapters, refs, message, () -> code.add("$L$N", "$", param.getCallableName()));
@@ -113,8 +113,8 @@ public class StaticProcessor extends GProcessor {
                     code.addStatement("$T.$N = $L", self.getTypeName(), param.getName(), TypeHelper.getDefaultValue(param.getType()));
                 } else {
                     code.addStatement("$T _$N = $L", param.getType(), param.getName(), TypeHelper.getDefaultValue(param.getType()));
-                    code.addStatement("boolean has_$N = false", param.getName());
                 }
+                code.addStatement("boolean has_$N = false", param.getName());
             }
             if (isEmpty) {
                 code.addStatement("reader.skipValue()");
@@ -127,30 +127,36 @@ public class StaticProcessor extends GProcessor {
                         param = altMap.get(param);
                         if (param == null) continue;
                     }
-                    code.beginControlFlow("case $S ->", getSerializedName(param));
-                    if (param.getType().getKind().isPrimitive()) {
-                        if (param instanceof Property.Field) code.add("$T.$N = ", self.getTypeName(), param.getName());
-                        else code.add("_$N = ", param.getName());
-                        Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
-                        code.add(";\n");
-                    } else {
-                        code.beginControlFlow("if (reader.peek() == $T.NULL)", Cl.GSON_TOKEN)
-                                .addStatement("reader.nextNull()");
-                        if (param instanceof Property.Field) {
-                            code.addStatement("$T.$N = null", self.getTypeName(), param.getName());
-                            code.unindent().add("} else $T.$N = ", self.getTypeName(), param.getName());
+                    List<String> names = getSerializedNames(param);
+                    for (String serializedName : names) {
+                        code.beginControlFlow("case $S ->", serializedName);
+                        code.addStatement("if (has_$N && !reader.isLenient()) throw new $T($S)", param.getName(), Cl.MALFORMED_DATA_EXCEPTION, "Duplicate entry for: " + names.getFirst());
+                        if (param.getType().getKind().isPrimitive()) {
+                            if (param instanceof Property.Field) code.add("$T.$N = ", self.getTypeName(), param.getName());
+                            else code.add("_$N = ", param.getName());
+                            Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
+                            code.add(";\n");
                         } else {
-                            code.addStatement("_$N = null", param.getName());
-                            code.unindent().add("} else _$N = ", param.getName());
+                            code.beginControlFlow("if (reader.peek() == $T.NULL)", Cl.GSON_TOKEN)
+                                    .addStatement("reader.nextNull()");
+                            if (param instanceof Property.Field) {
+                                code.addStatement("$T.$N = null", self.getTypeName(), param.getName());
+                                code.unindent().add("} else $T.$N = ", self.getTypeName(), param.getName());
+                            } else {
+                                code.addStatement("_$N = null", param.getName());
+                                code.unindent().add("} else _$N = ", param.getName());
+                            }
+                            Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
+                            code.add(";\n");
                         }
-                        Adapters.generateRead(param, spec, code, typeVariables, otherAdapters, refs, message);
-                        code.add(";\n");
+                        code.addStatement("has_$N = true", param.getName());
+                        code.endControlFlow();
                     }
-                    if (!(param instanceof Property.Field)) code.addStatement("has_$N = true", param.getName());
-                    code.endControlFlow();
                 }
-                code.add("default -> ")
-                        .addStatement("reader.skipValue()");
+                code.beginControlFlow("case String s -> ")
+                        .addStatement("if (reader.isLenient()) reader.skipValue()")
+                        .addStatement("else throw new $T($S + s)", Cl.MALFORMED_DATA_EXCEPTION, "Unexpected name: ")
+                        .endControlFlow();
 
                 code.endControlFlow()
                         .endControlFlow()
diff --git a/commons-serialize-generator/src/test/java/io/gitlab/jfronny/commons/serialize/generator/test/Main.java b/commons-serialize-generator/src/test/java/io/gitlab/jfronny/commons/serialize/generator/test/Main.java
index 54cf4c8..363f8d8 100644
--- a/commons-serialize-generator/src/test/java/io/gitlab/jfronny/commons/serialize/generator/test/Main.java
+++ b/commons-serialize-generator/src/test/java/io/gitlab/jfronny/commons/serialize/generator/test/Main.java
@@ -24,7 +24,7 @@ public class Main {
         public Boolean someBool;
 
         @GComment("Halal")
-        @SerializedName("bingChiller")
+        @SerializedName(value = "bingChiller", alternate = {"bingChiller2", "bingChiller3"})
         public String getBass() {
             return "Yes";
         }